The present invention relates generally to aluminum composite compositions and more particularly to and aluminum composite composition of increased homogeneous carbon content for creating a heat-treatable material that is harder, tougher, and lighter per volume than standard aluminum.
Heat-treating of aluminum parts is common practice, but one which is limited because it typically involves immersion of the aluminum part in high carbon concentration liquids which produces surface hardness but leaves a soft aluminum core. The resulting heat-treated aluminum parts have obvious deficiencies due to the inner core that was not hardened by the heat-treatment process. Heat-treating of metals, e.g., steel, is known to depend upon the carbon content of the metal. Unless the carbon content of the aluminum can be increased, it cannot be hardened to the same degree as can, for example, steel.
The need to materials that are strong and lightweight is obvious. Traditional materials that were lightweight were not sufficiently strong, and those that were strong, were too heavy. For example, the automotive industry would like to reduce the weight of vehicles to improve fuel economy without sacrificing safety and without prohibitively increasing the cost of the vehicle. Aluminum offers the weight reduction that they seek, but not the hardness of the steel that it replaces.
Heretofore, U.S. Pat. No. 5,401,338 proposes to make an aluminum alloy matrix composition by forming a heated, ultrasonically oscillated reinforcing material (Al2O3, SiC, SiN, etc.) aqueous suspension, which is sprayed onto the surface of heated aluminum held under continuous agitation. Degassing follows this procedure.
U.S. Pat. No. 5,021,087 proposes to improve the casting properties of aluminum by placing a hydrogen-containing treating gas blanket over molten aluminum.
U.S. Pat. No. 5,376,160 proposes to alloy Ti, Mo, B with iron or steel by adding granules of the iron or steel that encapsulate decomposable organic polymers (polyethylene, polypropylene, polystyrene) and the alloying metal. The molten iron or steel melts the granules, which releases the organic polymers that decompose into gas that agitates the melt.
U.S. Pat. No. 4,159,906 proposes to desulfurize pig iron with calcium carbide or calcium cyanamide and an agent (polyethylene, polyamide) that releases water or hydrogen at molten pig iron temperatures.
The present invention is addressed to hardening the complete hardening of aluminum parts.